Fe^(2+)活化CH_3X(X=H,Cl)中C—H,C—Cl键的理论研究  

A Theoretical Study on Activation of C—H and C—Cl Bonds in CH_3X(X=H,Cl) by Fe^(2+)

作　　者：孙小丽[1] 李吉来[1] 黄旭日[1] 孙家锺[1] 

机构地区：[1]吉林大学理论化学研究所、理论化学国家重点实验室,长春130023

出　　处：《化学学报》2012年第11期1245-1249,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.21103064;21073075和21173097);教育部博士点基金(No.20100061110046);吉林大学理论化学国家重点实验室专项基金;吉林大学基本科研业务费(Nos.421010061439;450060445067)~~

摘　　要：采用密度泛函理论(DFT)详尽地研究了Fe2+与CH3X(X=H,Cl)的反应机理.结果表明在所有通道中,反应4的H提取能垒最低(Ga=0.23 kcal/mol),氧化插入机制和SN2取代机制没有竞争性.详尽的电子结构分析表明由于金属3d与底物的σ*C—X可以最好的重叠,从而Fe2+从前端进攻C—X键有利于反应.该研究揭示了其微观本质,为Fe2+活化C—X键等相关研究提供理论线索和依据.The reactions of Fe2＋ with CH3X （X=H, Cl） have been studied by density functional theory method detailedly. The results demonstrated that the H abstraction in Eq. 4 can proceed via the lowest activation barrier （△Ga= 0.23 kcal/mol） in all feasible pathways. However, the mechanisms of oxidative insertion and the SN2 substitution are not competitive because of thermodynamic factors. The electronic structure analysis suggests that the overlap between metal 3d orbital and substrate σc x results in the preference of Fe2＋ front side attack on the C--X bond. This study is expected to shed light on the nature of the title reac-tions and provide theoretical clues and foundation for future research.

关 键 词：SN2 插入 抽提 反应机制 活化能 电子结构 

分 类 号：O621.13[理学—有机化学]